The present invention relates to a drilling machine operatively associated with a vacuum system so as to remove drill chips from a workpiece through an axial drill hole and more particularly, to an adapter fitted around the shank of a drill and designed to connect the drill with an external source of vacuum.
For the purpose of describing a known adapter, reference will first be made to FIG. 1.
As shown, in FIG. 1 a cylindrical adapter 10 is fitted around a drill 11. The drill 11 is composed of a shank 12 connected to a motor (not shown) and having a blind bore 14, and a body 16 rigidly received in the bore 14. The adapter 10 is rotatable relative to the shank 12. The body 16 has an axial through hole 18. The shank 12 has a plurality of radial holes 20 communicated with the axial through hole 18. An annular groove 22 is formed in the inner surface of the adapter 10 and communicates with the radial holes 20. The adapter 10 also includes a radial port 24 communicated with the annular groove 22. A fitting 26 is mounted on the outer periphery of the adapter 10. The fitting 26 has one end communicated with the port 24 and the other end connected to a vacuum hose H. Two annular grooves 28 are formed in one end of the shank 12 to receive two respective locking rings 30. The locking rings 30 are located at opposite ends of the adapter 10 so as to inhibit axial displacement of the adapter 10 along the shank 12. During a drilling operation, the shank 12 and the body 16 are driven for rotation by the motor whereas the adapter 10 is held against rotation.
To separate the body 16 from the shank 12, a cotter pin must be inserted into one of the radial holes 20 from the outside of the drill. To that end, the two locking rings 30 must first be removed from the shank 12 to allow separation of the adapter 10 from the shank 12. This removal requires a special tool and is cumbersome.
Accordingly, it is an object of the present invention to provide an adapter for connecting a drill with an external source of vacuum, which can readily be removed from the drill without the need for a special tool.